Re: gmirror failed with error 19.

On Thu, Nov 3, 2011 at 4:50 AM, Sascha Klauder <sascha_at_trimind.de> wrote:
> On Tue, 2011-11-01 11:23 +0400, Andrey V. Elsukov wrote:
>> On 28.10.2011 13:48, Sascha Klauder wrote:
>> >  GEOM_MIRROR: Device mirror/gm0 launched (2/2).
>> >  GEOM_PART: partition 1 has end offset beyond last LBA: 490350671 > 490350670
>> >  GEOM_PART: integrity check failed (mirror/gm0, MBR)
>> This is the main problem. Your MBR' slice is bigger than actual space
>> you have. The only way to fix this - recreate slice.
>
>  I've partioned and labeled the disk with sysinstall(8) from
> 8.2-RELEASE media.  Does 9.0 use different disk geometry cal-
> culation than 8.2 or is usage of gmirror the culprit?  Both
> 8.2 and 9.0 kernels report the disk having 490350672 sectors.
>
>> You can break your mirror, recreate the slice (NOTE: you must preserve
>> one sector for the gmirror's meta-data), then copy your data to the
>> newly created slice, then reboot from the new slice and recreate mirror.
>
>  I think I'd rather reinstall 9.0 from scratch, getting rid
> of MBR/disklabel as well.

While using gpart and the 9.0 installer has some real benefits, it
also has a few problems.

I ave a disk that I partitioned with bsdinstall from the 9.0
distribution media and it worked fine for a STAT disk, but I am unable
to boot te same disk when connected to a USB adapter. It shows up in
the boot list, but when I select it, the screen blanks for a few
seconds (<5) and the list re-appears. No errors, but my T520 BIOS
clearly is not happy with it. I have no idea how common htis issue
might be, but the T520 does have a UEFI BIOS.

As noted, GEOM wants the final sector on the disk for its metadata,
but GPT mandates that hte ast sector of the disk be used for a backup
of the boot sector. The leads to the potential ofr all kinds if
ugliness to develop, especially when BIOS, which knows nothing about
GEOM, is accessing the disk.
-- 
R. Kevin Oberman, Network Engineer
E-mail: kob6558_at_gmail.com